Solar energy conversion apparatus

ABSTRACT

Solar energy conversion apparatus including a housing portion, an energy absorbing portion, a fluid directing portion and a cover portion; the housing portion including a molded plastic pan member including a base section with upwardly extending spaced spacer sections, insulation covering the exposed surface of the base section to a depth less than the height of the spacer sections; the pan member including outwardly inclined sidewall sections having spaced inner and outer wall sections with a top section including an outwardly extending flange section and an inwardly extending slotted frame section; the energy absorbing portion including a conductive metal liner member positioned within the housing portion and resting on the upper surfaces of the spacer sections with flange sections extending outwardly from upper edges of liner sidewall sections and bearing on the top section of the pan member, conductive metal absorber members with spaced risers covering the bottom of the liner member; the fluid directing portion including a plurality of parallel spaced longitudinal baffle members arranged in a staggered relationship to provide a tortuous fluid path through the apparatus, an inlet opening and an outlet opening to the tortuous path, the baffle members extending upwardly from the liner bottom to a plane connecting the liner flange sections; the cover portion including transparent impact resistant flat and dome members, the edges of the flat member being secured to the top section through a peripheral frame section including a slot, the dome member being disposed over the flat member with its edges engaged with the flange section slots, the dome member including flat sections extending upwardly at an angle of 20° to 30° and a convex central section joining the flat sections.

This application is a continuation-in-part of pending application Ser.No. 80694, filed Oct. 1, 1979, abandoned.

This invention relates to a novel apparatus for the utilization of solarenergy and more particularly relates to a new apparatus for convertingsolar energy into energy forms which are capable of being used moreconveniently.

With the recent large increases in the cost of conventional energysources such as electricity and petroleum, both in the United States andforeign countries, much attention is being given to alternative energysources. One energy source which is especially appealing is solar energybecause of its unlimited supply and the absence of pollution and otherecological problems with solar energy.

Many of the solar energy systems heretofore proposed involve theabsorption of heat from the sun by gases or liquids and the circulationthereof to the areas requiring heat. If the heat is not fully neededwhen the sun is shining, the heated gases or liquids can be circulatedto storage chambers where the heated media is stored or the gas orliquid is passed over a heat absorbing material such as a bed of rockswhich will absorb and store the heat energy for subsequent recovery.

The gas or liquid generally absorbs the solar energy by exposure to therays of the sun. Since solar energy itself does not cost anything, theprincipal costs in solar energy systems are the initial expense of thesolar energy converting equipment and the subsequent expense ofoperating and maintaining the equipment. Ideally, it is desirable toincrease the temperature of the gas or liquid as much as possible duringeach pass through the equipment so a minimum amount of equipment will berequired to accomplish a desired amount of heating. Thus, improving theoperating efficiency of the solar energy conversion system can result ina significant savings both in capital investment and in operating costs.

Much effort has been expended on ways to improve the operatingefficiency of solar energy systems. It has been proposed to circulate agas or liquid through a closed system in which a portion of the systemis exposed to the sun. Some systems utilize black chambers in an attemptto increase the amount of heat energy absorbed. Other systems havetransparent portions in their solar energy converting sections.

Another consideration in the design of solar energy conversion systemsis how the system will be affected when the sun is not shining such asat night and on cloudy or rainy days. Most systems that are efficientwhen absorbing solar energy also release large amounts of energy whenthe sun is not shining.

In view of the conflicting objectives of high efficiency of solar energyabsorption and low heat loss when the sun is not shining, designs ofsolar energy conversion systems have included a variety of complicateddevices in an attempt to accomplish both objectives. Some systems employmovable panels to cover the absorption equipment when the sun is notshining. Movement of the panels is controlled by sensors that activatemotors to move the panels.

While some of the designs may reduce the loss of heat from the systemwhen the sun is not shining, they are very complicated and greatlyincrease the cost of the system. Also, such designs are subject tofailure and increase operating and maintenance costs.

The present invention provides a novel apparatus for converting solarenergy to a more useable form with improved operating efficiency. Theapparatus provides efficient utilization of solar energy with low heatloss when the sun is not shining. In addition, the solar energyconverter of the invention does not require movable panels or othermovable components to achieve these results. Further, the apparatus doesnot require sensors or motors since there are no movable panels to bechanged.

The solar energy converter of the invention is suitable for use withgases or liquids and combinations thereof. Moreover, the converter canbe combined with existing heating systems. The conversion apparatus ofthe invention is simple in design and is an active system without movingor driven parts. Also, the apparatus can be fabricated from commerciallyavailable materials relatively inexpensively.

Other benefits and advantages of the novel solar energy converter of thepresent invention will be apparent from the following description andthe accompanying drawings in which:

FIG. 1 is a schematic illustration of a heating system utilizing oneform of the solar energy conversion apparatus of the invention;

FIG. 2 is an enlarged top view in section of the solar energy conversionapparatus shown in FIG. 1;

FIG. 3 is a sectional view of the solar energy conversion apparatusshown in FIG. 2 taken along line 3--3 thereof; and

FIG. 4 is an enlarged fragmentary sectional view of the solar energyconversion apparatus shown in FIG. 2 taken along line 4--4 thereof.

As shown in FIG. 1 of the drawings, one form of the solar energyconversion apparatus 11 of the invention is combined with a conventionalhot air heating system. Inlet 12 of conversion apparatus 11 is connectedby a duct 13 including a fan 14 to a return register 15 located in aroom of a house. Outlet 16 of the converter 11 is connected by a duct 17to a fan 18 associated with a furnace 19. A duct 20 leads from furnace19 to a supply register 21 located in a room of the house. A storagechamber 23 having a bed of rocks 24 or similar material therein isconnected with fan 18 and furnace 19 through ducts 25 and 26.

Solar energy conversion apparatus 11 of the invention includes a housingportion 31, an energy absorbing portion 32, a fluid directing portion 33and a cover portion 34. Advantageously, the converter 11 has a lengthabout twice the width thereof and preferably about four feet by eightfeet.

The housing portion 31 includes a molded plastic pan member 36. The panmember 36 includes a base section 37. The base section 37 includesupwardly extending spacer sections 38. The spacer sections 38 are spacedfrom one another and preferably extend from one end of the pan member 36to the other end thereof. Insulation 39 fills the spacer sections 38 andcovers the exposed surface of the base section 37. The insulationcovering the base section 37 has a depth less than the height of thespacer sections 38. The base section 37 also includes downwardlyextending support sections 40.

Pan member 36 further includes outwardly inclined sidewall sections 42.The inclination advantageously is less than about 10°. The sidewallsections 42 include spaced inner and outer wall sections 43 and 44,respectively. The upper edges of the inner and outer wall sections 43and 44 are joined by top section 45. The top section 45 includes anoutwardly extending flange section 46 which advantageously also extendsupwardly. An inwardly extending slotted frame section 47 is located onthe flange section 46. Insulation 48 fills the space between the innerand outer wall sections 43 and 44. The insulation in the spacer sectionsand the sidewall sections preferably is a foam insulation.

The energy absorbing portion 32 of the apparatus 11 includes aconductive metal liner member 50. The liner member 50 is positionedwithin the housing portion 31. The liner member 50 includes asubstantially flat bottom section 51. The liner bottom section 51 restson the upper surfaces 52 of the housing spacer sections 38.

The edges of the bottom section 51 terminate adjacent the housingsidewall sections 42. The liner member 50 includes sidewall sections 53extending from the edges of the liner bottom section 51 upwardly to apoint closely adjacent to the top section 45 of the housing sidewallsections 42. Flange section 54 extends outwardly from the upper edges ofthe liner sidewall sections 53 and bears on the top section 45 of thepan member 36.

The energy absorbing portion 32 further includes conductive metalabsorber members 56. The absorber members 56 cover the exposed surfaceof the liner bottom section 51. The absorber members 56 include aplurality of spaced risers or undulations 57. The undulations 57 aredisposed transversely of baffle members 58 of the fluid directingportion 33 described hereafter. The liner member 50 and the absorbermembers 56 preferably are formed of aluminum.

A plurality of spaced baffle members 58-60 are disposed longitudinallyof the pan member 36. The baffle members 58-60 are arrangedsubstantially parallel to one another in a staggered relationship.Alternating baffles of the staggered relationship each have one endadjacent to a common end 62 of the liner member 50. The other end ofeach alternating baffle is spaced from the opposite end 63 of the linermember 50. Thus, alternating baffles 58 and 60 are attached to liner end62 and have their opposite ends spaced from liner end 63. Likewise,baffle 59 is attached to liner end 63 and the opposite end thereof isspaced from liner end 62. Advantageously, three baffles are employedformed of aluminum.

This alternating arrangement of the baffles 58-60 provides a tortuousfluid path through the apparatus 11. The inlet opening 64 is locatedadjacent one end of the tortuous path and an outlet opening 65 islocated adjacent the opposite end of the tortuous path. The inlet 64 andthe outlet 65 preferably are located at a common end of the apparatus.The baffles 58-60 extend upwardly from the liner bottom section 51. Aspointed out above, the raised undulations 57 of the absorber members 56are disposed transversely of baffle members 58-60, that is,perpendicular to the tortuous path through the apparatus 11.

The cover portion 34 of the energy conversion apparatus 11 of theinvention includes a transparent flat member 67 and a similar domemember 68. The flat and dome members 67 and 68 are formed of impactresistant material. Advantageously, the flat and dome members are formedof polycarbonate plastic.

The flat member 67 rests on the peripheral top section 45 of the panmember 36. The flat member 67 also bears on the free upper edges of thebaffle members 58-60. The edges of the flat member 67 are secured to thetop section 45 around substantially the entire edge thereof. Thisattachment of the flat member to the top section is through a peripheralframe section 69. The frame section includes an inwardly extending slot70 which engages the edge of the flat member.

The dome member 68 is disposed over the flat member 67. The dome member68 as shown extends beyond the edges of the flat member. The edges ofthe dome member 68 fit into and are engageable with slots 47 of theflange section 46 of the pan sidewall sections 42.

The dome member 68 includes substantially flat side sections 73 and 74.The flat sections 73 and 74 extend upwardly from the longitudinal edges75 and 76 of the pan member 36. The flat sections extend upwardly towardone another at angles between about 20° and 30° to the flat member 67.

The flat side sections 73 and 74 are joined by a convex central section77. The convex section 77 extends longitudinally of the apparatus 11.Thus, the ridge of the convex section 77 is substantially aligned withthe baffles 58-60. The distance between the ridge of the convex centralsection 77 and the flat member 67 preferably is greater than the heightof the housing portion 31 of the conversion apparatus 11.

In the operation of the heating system shown in FIGS. 1-4 of thedrawings, air is withdrawn from a room of a house through returnregister 15 and duct 13 by fan 14 and transferred to solar energyconverter 11. Converter 11 may be mounted on the roof of the house or asimilar location which provides good exposure to the sun. The uniqueconfiguration of dome member 68 provides a high level of heating evenwhen the sun is not directly overhead as compared with previous solarcollectors.

The air circulating through converter 11 around baffles 58-60 is heatedby the rays of the sun shining thereon. The heated air exits throughduct 17 and passes through fan 18 associated with furnace 19. The heatedair leaves furnace 19 and is forced by fan 18 through duct 20 and supplyregister 21 into the room.

If heat is not required in the rooms of the house, the heated air may bediverted by suitable dampers 27, 28 and 29 in ducts 13, 17, 20 and 25into storage chamber 23. The heated air passes over rocks 24 withinchamber 23 transferring heat to the rocks. The air then may berecirculated to converter 11. If heat is required in the house when thesun is not shining, air is withdrawn from the rooms and circulatedthrough storage chamber 23. The air passing over rocks 24 therein picksup heat from the rocks and is forced by fan 18 through duct 20 andsupply register 21 into the room.

The above description and the accompanying drawings show that thepresent invention provides a novel solar energy conversion apparatus forchanging solar energy into a more useable form. Furthermore, theconversion apparatus of the invention provides efficient utilization ofsolar energy with low heat loss when the sun is not shining. The solarenergy converter does not require movable panels or the sensors andmotors needed to operate them.

The solar energy converter of the present invention is suitable for usewith gases or liquids and combinations thereof. In addition, theconverter can be combined with existing heating systems. Moreover, theconversion apparatus is simple in design without moving or driven parts.Also, the conversion apparatus of the invention can be fabricated fromcommercially available materials relatively inexpensively.

It will be apparent that various modifications can be made in theparticular solar energy conversion apparatus described in detail andshown in the drawings within the scope of the invention. For example,the size and configuration of the converter can be changed to meetspecific requirements. Also, more than one converter can be used inparallel or series to increase the capability of the system. Inaddition, the arrangement of the inlets and outlets and the baffles canbe different as desired. Therefore, the scope of the invention is to belimited only by the following claims.

What is claimed is:
 1. Solar energy conversion apparatus including ahousing portion, an energy absorption portion, a fluid directing portionand a cover portion; said housing portion including a molded plastic panmember, said pan member including a base section, said base sectionincluding upwardly extending spacer sections, said spacer sections beingspaced from one another, insulation covering the exposed surface of saidbase section, said base-covering insulation having a depth less than theheight of said spacer sections, said base section including downwardlyextending support sections, said pan member including outwardly inclinedsidewall sections, said sidewall sections including spaced inner andouter wall sections, the upper edges of said inner and outer wallsections being joined by a top section including an outwardly extendingflange section with an inwardly extending slotted frame sectionextending from said flange section, insulation filling the space betweensaid inner and outer wall sections; said energy absorbing portionincluding a conductive metal liner member positioned within said housingportion, said liner member including a bottom section, said liner bottomsection resting on the upper surfaces of said housing spacer sections,the edges of said bottom section terminating adjacent said housingsidewall sections, said liner member also including sidewall sectionsextending from the edges of said liner bottom section upwardly to apoint closely adjacent to the top section of said housing sidewallsections, flange sections extending outwardly from the upper edges ofsaid liner sidewall sections and bearing on said top section of said panmember, conductive metal absorber members covering the exposed surfaceof said liner bottom section; said absorber members including aplurality of spaced risers, said fluid directing portion including aplurality of spaced baffle members, said baffle members being disposedlongitudinally of said pan member and substantially parallel to oneanother, said baffle members being arranged in a staggered relationshipwith alternating baffles each having one end adjacent to a common end ofsaid liner member and the other end of each alternate baffle beingspaced from the opposite end of said liner member to provide a tortuousfluid path through said apparatus, an inlet opening adjacent one end ofsaid tortuous path and an outlet opening adjacent the opposite end ofsaid tortuous path, said baffle members extending upwardly from saidliner bottom section to a plane connecting the liner flange sections,said risers of said absorber members being disposed transversely of saidbaffle members; said cover portion including transparent impactresistant flat and dome members, said flat member extending between saidtop section of said pan member and bearing against the free upper edgesof said baffle members, the edges of said flat member being secured tosaid top section around substantially the entire edge thereof through aperipheral frame section including an inwardly extending slot engageablewith the edge of said flat member, said dome member being disposed oversaid flat member and extending beyond the edges of said flat member, theedges of said dome member being engageable with said inwardly extendingslots of said flange section of said pan sidewall sections, said domemember including substantially flat sections extending upwardly from thelongitudinal edges of the pan member toward one another at anglesbetween about 20° and 30° to said flat member and a convex centralsection joining said upwardly extending flat sections extendinglongitudinally of said apparatus.
 2. Solar energy conversion apparatusaccording to claim 1 wherein said sidewall sections of said pan memberare inclined to the vertical less than about 10°.
 3. Solar energyconversion apparatus according to claim 1 wherein said insulation insaid sidewall and spacer sections of said pan member is a foam.
 4. Solarenergy conversion apparatus according to claim 1 wherein said bottomsection of said liner member is substantially flat.
 5. Solar energyconversion apparatus according to claim 1 wherein said sidewall sectionsof said liner member are substantially parallel to said sidewallsections of said pan member.
 6. Solar energy conversion apparatusaccording to claim 1 wherein said liner member, said absorber membersand said baffle members are formed of aluminum.
 7. Solar energyconversion apparatus according to claim 1 wherein said apparatusincludes at least three baffle members.
 8. Solar energy conversionapparatus according to claim 1 wherein said inlet and outlet openingsare located adjacent a common end of said apparatus.
 9. Solar energyconversion apparatus according to claim 1 wherein said risers are raisedundulations.
 10. Solar energy conversion apparatus according to claim 1wherein said transparent flat and dome members are formed ofpolycarbonate plastic.
 11. Solar energy conversion apparatus accordingto claim 1 wherein the distance between the ridge of said convex centralsection of said dome member and said flat member is greater than theheight of said housing portion.
 12. Solar energy conversion apparatusaccording to claim 1 wherein said spacer sections are elongated andextend from one end of said pan member to the other.